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General => Technical support => Topic started by: ckane on June 10, 2012, 08:04:50 AM

Title: Momentary Relay operation
Post by: ckane on June 10, 2012, 08:04:50 AM

Newbie here.

Using a custom function, how does one operate a relay on a momentary basis?  I want to emulate the function of a momentary push button.  

For example, I have an INIT Input which is a manual push button, but I want to either programmically operate a relay contact in parallel with the input or call the custom function that this input operates.

Title: Re:Momentary Relay operation
Post by: ckane on June 10, 2012, 08:24:59 AM

As an update, I can call the function, but what I really want to do is emulate the push button.  I have stanard start/stop circuit with manul buttons, but I want to program the stop input.  So when the process completes, I want to emulate pressing the stop button.

Title: Re:Momentary Relay operation
Post by: support on June 11, 2012, 09:09:21 AM

You could actually turn on the STOP input for one scan time by running the command SETIO STOP (assuming your STOP button is so labelled in the I/O table).

You should ensure that the function calling SETIO STOP precede the ladder circuit that STOP is driving. This way it has a chance to be executed by the ladder scan before the I/O scan set it back to OFF state.